DESCRIPTION (Taken directly from the application) The goal of this specialized center of research SCOR application is to understand the clinical biological and biochemical consequences of mutationsin the cystic fibrosis transmembrane conductance regulator (CFTR), the gene defective in cystic fibrosis (CF). The program brings together scientists and clinicians with a broad range of expertise to analyze the effects of mutant CFTR function from the disease in patients to the effects on cells to the changes in the structure of the protein. The broadening picture of the phenotypic range of CF emphasizes the vital role that CFTR plays in epithelial tissues. The deficiencies in specific tissues as well as the general manifestations of the disease resulting from different molecular defects have implications for the design of therapeutic strategies to treat CF. The SCOR is organized into four Research Projects (RP), two Pilot Projects (PP), and three Core Units, grouped into three research areas. In the first area, RP1 will define the spectrum of phenotypic expression in patients with CFTR mutations and correlate phenotypic differences in disease expression with specific mutations in CFTR. In addition to patients with typical manifestations of CF, the specific aims of this project will characterize patients with atypical manifestations define the range andseverity of phenotypes in different genotype classes and correlate mutations to the various phenotypes. The second area of research deals with CFTR function at the cellular level. The biophysical properties of the various mutant forms of CFTR as defined from the patient studies will be studied in RP2 with the use of purified protein in reconstituted lipid bilayers; the goals are to define the nature of the regulation of the wild type and mutant CFTRs by ATP binding or hydrolysis and to determine whether interaction occurs between CFTR molecules. RP3 will dissect the intracellular processing of CFTR in epithelial cells by examiningmutants that appear blocked from delivery to the apical membrane. A specific focus will be the study of mutant proteins seen in pancreatic sufficient patients known to have milder symptoms. PP1 will develop anovel method for analyzing the function of CFTR in intracellular membranes. The third area of investigation will be the structural analysis of regions (domains) of CFTR using biophysical methods. RP4 will use circular dichroism (CD) to study structure function relationships in the transmembrane domains of wild type and various mutant forms of CFTR. PP2 will define regions of the first nucleotide binding fold and the R domain that allow soluble over-expression in bacteria. These will then be used for structural studies using nuclear magnetic resonance spectroscopy to compare wild type and mutant forms. In addition to the Administration Core, theCF patient database and the Protein and Expression Core will serve to support the above projects. The results from SCOR should lead to insights into the molecular mechanisms of CF pathology and should provide suggestions for improved therapeutic approaches.